So I spoke with the team doing the video recordings this year about 5 weeks ago. This is what I know:
*Last year, all the talks were recorded, which cost a lot, and then very few people watched them, so (this was not my decision) the decision was made to only record particular talks this year.
*No livestreams were available.
*The video team that has been hired has been instructed to incorporate .webm conversion and uploading to commons into their workflow, so expect them to upload as soon as they can. I don;t know when this will be.
*All the footage that the video team is shooting will be owned (copyright) by Wikimedia Mexico per their contract, so if there are particular clips you want later, contact WMMX.
Per Nkansah's point: I don't recommend buying 10 cameras - the cost of shipping, storing, maintaining all that gear is cumbersome and as the years go on, most cameras will go 'obsolete' - they will function but not be up to moderns standards. For those reasons I do recommend renting gear in locations for large productions, like Wikimania.
Hope this helps!